Changeable-speed gear.



No. 773,005. PAIENTED'OGT 25, 1904. v H. DRESES.

GHANGEABLE SPEED GEAR.

APPLIUATION FILED MAY 16, 1904. No MODEL. "'71: g. Z z SHEETS-SHEET 1.

N0."773,0o5. Y PATBNTBD 00T. 25, 1904.

' gH. DRESBS.l

GHANGEABLE- SPEED GEAR. PPLIUTION FILED MAX 164| 1904.

NO MODEL. l ZBHEBTS-SHEET 2.

Patented october 25, 1904*.

PATENT @trice-g HENRY DREsEs, lor CINCINNATI, omo. y f

GHANe.EABLE-SPEEn` GEAR.

SPECIFICATION forming part of Letters Patent N o. 773,005, dated October 25, 1904.

i Applicatioi1 filed May 16, 1904. Serial No. 208,266.' v(No model.)

vTo all whom tm/'tty concern! Be it known that I, HENRY DREsEs, a citizen of the United States, residing in the city of Cincinnati, in the county of Hamilton and State of Ohio, have invented certain new and useful Improvements in Changeable-Speed Grears; and l dodeclare the following to be a clear, full, and exact description thereof, at#

tention being called to the accompanying two sheets of drawings, with thereference characters marked thereon, which form also a part of thisspecification. K y

This invention relates to .improvements in changeable-speed gear, being a device whereby in a machine-toohfor instance, the speed by which the power is transmitted to it may be varied. These devices are therefore placed in an intermediate positionbetween such machine-tool and the source of power for drivingit, which is usually a line or counter shaft.

The invention consists of certain features 'of' construction whereby certain objections now inherent in. such devices are removed. One of these objections is liability to injury of the machinery, breakage, and stripping off A of teethwhen changing abruptly from a slower to a higher speed, and all of which is avoided by my improved construction, which further is of sucha character as to permit 1 prompt adjustment by means of convenient manipulation and engagement of the parts only when in proper working position.

In the following specification, and particu- `larly pointed out in the claims, is` found a full description of the invention, together with its operation and manipulation, parts, and construction, which latter is also illustrated in the accompanying two sheets of drawings, in.

whichv v Figure 1 is a top view of the'device with parts broken away and others in section.

Fig. 2 is a front View of it, parts of the genv eral frame being broken away and other parts being also shown in section. Fig. 3 is an end view of the device and as shown in the preceding figures. Figs. 4E' and 5 show the driving-pulley of the device in sectional view and as these views appear if a section is taken on line 4 4: of Fig. 1. Fig. 6 is a side view ofthe l in the. drawings.

driven one of the 'first set of gear-wheels, being the slowest gear-train, and as such wheel appears if a section is taken on line 6 6 of Fig. 1. Fig. 7 is a vertical cross-section ofthe preceding figure, both being enlarged. Fig. 8 in a view similar to the corresponding parts as they appear in Fig. 1 .shows a modified construction of these parts, they constituting the means whereby the motion of the device is delivered tothemachine to lbe operated.

In the drawings, 10 indicates the drivingshaft of the device receiving motion from a suitable sourceof power Vobtained from a motor direct or through the intervention of a line or counter shaft. 11V is the pulley ywhich drives vthis shaft, and 12 is its loose mate, upon which the belt is shifted'when the device is not used.

13 is the driven shaft, it being alsothe shaft which is operatively connected to the machine or machine-tool driven by this device.

from the drive-shaft to the driven one therevare `sets of gear-trains each consisting of two wheels mounted on these shafts, the faces of the' complementary gear-wheels being opposite each other, but not in mesh, and their diameters being graduated in the usual manner to obtain different speeds and as best seen The two wheels of a set are engaged so as to operate by means of an idler 14, which simultaneously engages the two and which is supported .so as to be adjustable laterally-across the faces of all the wheels and capable of engaging any set of them, so that, each of the sets transmitting a different speed, the adjustment of such idler and engagement by it of any particular set permits any of the available speeds to be transmitted to. the driven shaft and by it to the machine to be operated.

For purposes of so manipulating the'idler the same is mounted on a hand-lever 15, at oneend of which there is a bearing 16, by' which it is mounted on a guide-rod 17 and on whichk y this lever, with the idler, may be laterally adf justed to meet any of the sets ofl gear-wheels,

the manipulation being a lifting of the handlever, movement of it laterally, and dropping of it when in the proper position so as to simultaneously engage the two gear-wheels of a set.

Since the points where the idler engages the various sets of gear-wheels are not in a line parallel to rod 17 or to the shafts, it is also necessary that the pivot of lever 15 be amovable one, so that the idler meet the particular point of engagement. For such purpose this rod is supported on arms 18, one at each end, which arms are again pivotally attached to the general frame or housing of the device. By these means the idler may be moved to meet all positions for engaging any of the sets of gear-wheels. In shifting the idler it is essential that the new position may be quickly found without unnecessary movements and be at once secured and held. This means that the idler should not be lifted higher than necessary, yet at the same time sufficiently high to clear the intermediate sets of wheels over which it is passed to prevent striking them, which since they are in motion would be especially objectionable.

To prevent lifting higher than necessary, I provide a stop 19 on the under side of the hand-lever, which limits its lift when coming in contact with the under side of a shelf or ledge 20, upon which the lever normally rests and which shelf projects from the frame of the device. To compel sufficient lift to prevent the idler from scraping againstintermediate gear-wheels while adjusted laterally, there is a projection or pin 22 on the under side of thehand-lever which when this latter is raised to proper height and shifted laterally prevents by its contact with shelf 2O lowering of the hand-lever in improper position except said pin has arrived over one of anumber of'openings 23 in said shelf, one for each set of wheels, in which case only the handlever may be dropped sufiiciently to effect working engagement-that is, mesh of the idler with both wheels of the particular geartrain. When in such proper position, the idler is also locked by means of aspring-actuated locking-bolt2-1, adapted to engage one of a number of openings 25 in the front side of shelf 2O and manipulated in a manner usual with such devices. These openings 25 are so located that this locking is only possible when the idler is in proper position, as determined by pin 22 in conjunction with openings 23, the engagement of these openings by pin 22 and bolt 24 being a simultaneous one.

To facilitate the manipulation and adjustment of the hand-lever, particularly its lateral shift, there are two additional handles 26, both or either one of which may be used in conjunction with the handle on the lever.

groove 21 in shelf 2O serves as a guide in this lateral adjustment, pin 22 moving in it and never leaving it even after raised from openings 23, which latter are in the bottom of said groove. Thus the idler while being adjusted laterally is confined to move in a line above the points of meshing contacts, so that when dropped it will drop in proper position only and requires never any transverse adjustment to find a point of contact. lalso make provision to overcome by means of an easy transition the high resistance momentarilycreated to prevailing driving power when changing to a faster speed to lessen as much as possible the objectionable effects of sudden jars and impacts, thus avoiding injury to machinery by breakage of teethor otherwise. This occurs when the faster-rotating drive-shaft encounters the resistance due to the inertia of the stationary or slower-moving machinery or, what is the same, when this latter receives the sudden impetus of the faster motion. As to one of these provisions, 1 arrange that the driven shaft is always rotated at the slowest speed, 'so that in case any higher speed is to be used the resistance which the drive-shaft encounters is lessened to an extent equal to the difference between machinery at a standstill and machinery in motion, or, in other words, when starting work at a higher speed the start is not made with machinery at a dead stop, but with machinery in motion. This continual rotation at slowest speed refers of course only to such times when possibility of using the particular machine-tool exists; otherwise loose pulley 12 would carry the belt or even this latter would be entirel,7 at rest. This continual motion mi ghtbe effected in this way: that the idler-wheel after every action with a faster gear-train is shifted back lo the slowest gear-train, which arrangement being left to the operator is, however, not altogether satisfactory and not as reliable as a permanent arrangement which is contimially operative without requiring adjustment or attention. For such purpose l provide a stationary idler 27, which is continually in mesh with the slowest gear-train and always ready to transmit motion from one shaft to the other. (See also Fig. 6.) The :uljustable idler 14 is therefore not needed to operate. this slowest gear-train` and to prevent all possibility of the former being thrown into gear I omit in front of this gear-train the opening 23, which would be necessary to receive pin 22 in order to permit the hand-lever, with this idler, to be lowered into mesh. To prevent interference by this permanent gear engagement with any of the other faster gear engagements whenever they are established, this first or largest gear-wheel on the driven shaft (indicated at 28) is loosely mounted and provided with a recess in its side which contains a ratchet-wheel 29, rigidly mounted and to which the motion of wheel 28 is transmitted by means of pawls 31, kept in engagement by means of springs` as shown in Fig. 6. The action is a pushing one that is, the ends of the pawls push against the teeth of the ratchet-wheel. When now any of. the faster gear-trains is thrown into operation, causing the drive-shaft to rotate faster, this ratchet-wheel will simply move ahead and away from the pawls, these latter slipping over the teeth and no interference results. The driven shaft rotates at the faster speed, and while the slower gear' 28 rotates also it transmits no motion. All the other gears on shafts and 13 are rigidly mounted in the usual manner. l. Another and'second means to ease this momentary resistance by a retarded transition from a slower to a higher speed is by yieldingly mounting the driving-pulley 11 on shaft 10. For such purpose this drive-pulley is looselyT mounted and has also a recess in its side which is occupied by a rigidly-mounted disk 32. This disk fills this recess, with the exception of an annular recess or space around its edge, which, with the adjacentinner surface of the pulley, forms a spring-housing 33, which is occupied by a spring 34. One end of this spring bears against a plug'35, projecting from disk 32, and theother end bears against a plug 36, projecting from pulley 11.

, If now a higher speed-gear is suddenly thrown against plugr 25 on the disk.

in, the momentary resistance is diffused over a part of the rotation and to an extent equaled by the compression of the yielding spring,

which by plug 36 onthe pulley is compressed (See Fig. 5.) This yielding transition fromy a lower speed or resistance to a higher one and accompany'- ing compression of the spring is limited by means whereby the driving engagement ofv pulley 11 to its complementary disk becomes a positive one. This is done by a projection or stop on one'of the complementary parts engaging' a stop on the other part. For such purpose there is between the plugs a curved rod 37, which occupies the space surrounded vby the coils of the spring and the free end of which rod in due time encounters the other plug. After the momentary increase. in resistance due to a speed change hasbeen overcome spring 34 may expand again until, the

plugs rest against each other, as shown in Fig.

v 4. There is finally a third means to overcome by easy transition themomentarily-created higher resistance due to a change ofspeeds. This is at the point where operative connection is made between the driven shaft 13 of this device and the part or driving-shaft of the particularapparatus, machine-tool, &c., which by means of this changeable gear-train is driven from shaft 10. at 38 in the drawings, andthe connection for transmitting motion from shaft 13 may be made in two ways.

. LAs shown in Fig. 1, transmission by gearwheel is had, one, 39, being rigidly mounted on shaft 38.v The other gear, 41, is carried on arigidly-mounted sleeve 42 and to which it is held by frictional pressure, thus providing possibility of a limited slippage when excess- This shaft is shown for the moment prevailing driving power,

l whichslippage, however,v ceases when this resistan ce is overcome and after the slower moving machinery has assumed the higher speed.

To provide for this frictional engagement of this gear-wheel 41, sleeve 42 is in two parts, cach having aflange 43 at its end which project'over the sides of the wheel. Suitable friction-promoting material, like leather or liber, is placedbetween these flanges and the wheel, and the frictional engagement is adjusted and maintained by means of a nut 44, whereby the flanges of the sleeve, with this material between them, are caused to impinge against the sides of 'the gear-wheel. In some cases there is no such intermediate shaft 38-that is, no operatively-connected shaft--and shaft 38. onthe machine-tool is practically a continuation of driven shaft 13 of the speed-gear device. In such case shaft 38 is in line with shaft 13, as shown in Fig. 8, the two being directly connected at their ends. The connection is also one by frictional engagement, permitting a limited slippage and is somewhat similar to the engagement between the complementary parts of a friction-clutch, each part mounted at the. end of one of the shafts, with the exception that the parts are not movable to or from each other like in a clutch. is as follows: One shaft carries immovably In detail this construction attached to it a cup 45. Keyed to the other v shaft, but .free `to move longitudinally, is a' flanged sleeve 46. Between the two is a washer 47, of friction-promoting material, leather or fiber. .The two are held to each other with this washer clamped' between by a nut 48, which engages the cup and which permits also adjustment of the frictional impingement. This nut does, however, not bear directly against the sleeve, but reaches thislatter by means lof an interposed follower 49, locked for Vrotation to cup 45 by means of a key 51 and in a manner which does not interfere with the limited movement of nut 48 for adjusting IOO the friction. This cup and nut 48, seated on it,

one at the initial point, where the power is received, (pulley 11,) and the other at the point whereV the power isdelivered lfrom shaft 13 to shaft 38, onemight take the place of the other-that is, the connection yielding' by friction on shaft 13 and applied 'to' gear 41 might be applied to the sides-of pulley 11 andthe connection yielding by spring might be applied to gear-wheel 41, or the yielding devices might be alike at both points, either one only being used.

It will now be seen that by means of this device constructed as described the speed may be readily and conveniently changed while the parts are in motion without incurring the risk of injury or breakage of teeth when the idler is suddenly thrown into mesh. This is because of the yielding connections shown,which slip and yield when changes are made and at which times the strain and jar incident to such changes is beyond the ordinary driving power of the machinery.

Having described my invention, I claim as new:

l. In a speed-changing deviee,the combination of a drive and a driven shaft, a series of gear-trains arranged and graduated so that each when in operation transmits to this driven shaft a speed different from' the other, an idler, a hand-lever on which it is carried. a rod on which this hand -lever is pivotally mounted and on which it may be laterally adjusted so that the idler on it may engage any of the gear-trains, arms on which this rod is supported at both its ends and on which it may swing transversely to carry the idler to the proper point of engagement and means to lock the hand-lever in the position to which it has been adjusted.

2. In a speed-changing device, the combination of a drive and a driven shaft, a series of gear-trains arranged and graduated so that each when in operation transmits to the driven shaft a speed different from the other, an idler, a pivotally attached hand -lever on which it is carried and whereby it may be moved to meet for engagement any of the gear-trains, a shelf on which this lever normally rests, a stop on the under side of this lever projecting' under the shelf mentioned and adapted to engage the same so as to limit thereby the lift of the lever and means to lock this latter in position after adjustment.

3. Ina speed-changingdevice, the combination of a drive and a driven shaft, a series of gear-trains arranged and graduated so that each when in operation transmits to the driven shaft a speed different from the other, an idler, a pivotally attached hand -lever on which it is carried and whereby it may be moved to meet for engagement any of the gear-trains, a pin on the under side of this lever and a shelf with openings on which this lever normally rests with its pin occupying one of these openings and from which position the lever cannot be moved to engage the idler with any other train unless this pin is first lifted out of such opening, the arrangement being such, that such lift to permit such movement must be of such extent as to prevent engagement with any gear-train in intermediate or improper position and the lever cannot be dropped except the pin on it is above another opening.

4. In a speed-changingdevice, the combination of a drive and a driven shaft, a series of gear-trains arranged and graduated so that each when in operation transmits to the driven shaft a speed different from the other, an idler, a pivotally-attached hand-lever on which it is carried and whereby it may be moved to meet for engagement any of the gear-trains, a shelf on which this lever normally rests, a series of openings provided in this shelf, a pin projecting froln the under side of the lever, preventing` by its contact with the shelf engagement of the idler with a gear-train when in improper position except said pin occupies one of the openings mentioned and means to loch the hand-lever in its adjusted position.

5. In a speed-changingdevice, the combination of a drive and a driven shaft, a series of gear-trains arranged and graduated so that each when in operation transmits to the driven shaft a speed different from the other, an idler, a pivotally-attached hand -lever on which it is carried and whereby it may be moved to meet for engagement any of the gear-trains, a shelf on which this lever nermally rests, a series of openings provided in this shelf, and a spring-actuated locking-bolt carried on this hand-lever and adapted to loci; it in position by occupying` one of these openings.

6. In a speed-changingdevice, the combination of a drive and a driven shaft, a series of gear-trains arranged and graduated so that each when in operation transmits to the driven shaft a speed different from the other, an idler, a pivotally-attached hand-lever on which it is carried and whereby it may be moved to meet for engagen'ient any of the gear-trains, a shelf on which this lever normally rests and which is provided with openings, a series on its upper sidA and a series in its front side, a pin projecting from the under side of the lever, preventing by its contact with the shelf, engagement of the idler with a gear-train, except said pin occupies one of these openings in the uppersidc of the shelf and a spring-actuated locking-bolt, also carried on this hand-lever and adapted to enter one of the openings in the front side only when entrance of the pin in one of the other openings has permitted the hand-lever to drop in proper position.

7. In a speed-changing device, the combination of a drive and a driven shaft, a series of gear-trains, arranged and graduated so that each when in operation transmits to the driveshaft a speed dilierent vfromthe other, an idler, a hand-lever on which it is mounted, a movable pivot on which this hand-lever is supported so that the idler is free to be carried laterally to any gear-train for engaging the same, means to guide the hand-lever during IOO IIO

IIS

this lateral movement so that it is confined to move in a line above the points at which meshing contact may take place and a locking device to hold it in its adjusted position.

8. In a speed-changing device, the combination of two parallel shafts, graduated gears arranged in sets mounted on them, an idler, a hand-lever on which it is carried,`a movablysupported rod arranged parallel to the shaft on which the hand-lever is pivoted and whereby the hand-lever is permitted to carry the idler to a position to meet any gear set, a shelf on which this lever normally rests, a groove in this shelf arranged at an angle to the shafts mentioned and a projection on the hand-lever which occupies this groove and serves as a means to guide this lever during its manipulation to proper meshing contact in a horizontal plane.

9. In a speed-changing device, the combination of a drive and a driven shaft, gear-wheels on each rigidly mounted opposite each other and arranged to form sets graduated for speed, an adjustable idler wherebyv by its engagement with any of the gear sets variable speeds 4 may be'transmitted to the driven shaft, an additional set of gear-wheels proportioned to transmit to the driven .shaft a speed slower than any of the othersand a permanently-located idler which constantly operates this set,

may be transmitted to the driven shaft, an adf ditional set of gear-wheels proportioned to transmit to the driven shaft a speed slower than any of the others, one being rigidly mounted and the other provided with a recess in its side, a rigidly-mounted ratchet-wheel4 occupying this recess, pa'wls whereby this latter gear-wheel acts upon the ratchet-wheel in a manner to rotate its shaft and a permanentlylocated idler which constantly operates this set ina manner permitting the driven shaft to assume at any time the faster speed as transmitted by any of the other gear sets.

In testimony whereof I hereunto set my signature in the presence o f two witnesses.

HENRY DRESES. Witnesses: C. SPENGEL,

ARTHUR KLINE. 

